/Engine/Plugins/Media/PixelStreaming/Source/PixelStreaming/Public/IPixelStreamingStreamer.h
Set the Layer Preference for a specific player. Only useful if using the SFU.
void SetPlayerLayerPreference ( [FPixelStreamingPlayerId](API\Plugins\PixelStreaming\FPixelStreamingPlayerId) PlayerId, int SpatialLayerId, int TemporalLayerId )